Hundreds of tonnes of stone have been lifted by a giant crane into the River Tavy at Tavistock this week as work begins on a major repair to the river bank wall.

The stone, which has been bagged up for about 50 metres on the road, is to be used to build a temporary dam in the river, behind which the repairs will be carried out.

The wall has been eroded over the decades by the fast flowing water and is in danger of falling into the river and causing the undermining of Market Road which runs behind Brook Street and the Pannier Market.

Market Road, which serves the back of Brook Street businesses and enables market traders to load their wares, is closed this week and parking has been stopped for the duration of the project, to allow works vehicles and equipment to be stored. Traffic control measures will be in force.

The major capital works are funded by Tavistock Town Council as a priority the financial year because of the wall’s role in the structure of the river bank.

In consulation with the Environment Agency (EA) and other relevant agencies, it has been agreed the local stone can be left in the river after the project has completed in September, without harming the environment and habitats.

The dam will hold back the water, giving workers a dry space on the river bed to rebuild the holes in the wall.

The council says the 150-year stone wall is a form of flood protection measure, but the EA says it is not a formally designated flood defence.